In manufacturing processes, particularly those involving the fabrication of semiconductor wafers having circuit patterns thereon, computers are typically employed to control and monitor the automated manufacturing process. A variety of input/output devices (I/O) are used in the automated manufacturing process. For example, a variety of gases are employed. The gases are measured using flow meters and their introduction is controlled using valves. The temperature of gases and components is monitored at various locations. Pressure is monitored throughout the manufacturing facility. Robot manipulators are often employed. The manipulators are controlled and certain movement parameters, such as the revolutions per minute (RPM) of spinning wafers within the production facility are monitored. Likewise, other manufacturing process parameters may require monitoring at various times.
Most monitoring is accomplished using a display screen that is part of the user interface of a control computer. A conventional CRT screen is often employed. The process parameters are typically provided in alphanumeric form or as isolated graphs at a variety of locations on the display screen.
The scales used for different display graphs may vary widely. Where several plots or bar graphs for a given parameter are displayed, often the desired baseline value for each parameter varies. This causes the respective graphs to have varying sizes relative to each other. Such graphs are difficult to read at a glance, resulting in operator inefficiency, and the risk that improper readings will be made by an operator. In addition, there is often no standard for deciding whether information is to be displayed graphically, alphanumerically, or both. Warning information is also displayed in a variety of nonstandard ways.
In view of these disadvantages, it is an object of this invention to provide a computer graphical display that is more-easily readable, and standardized in format. The graphical display should be organized so that all significant parameters are clearly and logically displayed and so that all alarm conditions or unacceptable measurements are clearly indicated to the operator.